Ever Seen a Pika?

An article by frank

Ever Seen a Pika?

Found in nine western states and several western Canadian provinces, the American Pika looks more like a hamster than the hares to which it’s related. But though it may be rodent-sized—just nine inches long and weighing only about six ounces—the Pika’s a card-carrying member of the Lagamorph order, which includes rabbits and hares.

It’s one of two North American species (the other, the Collared Pika, lives in Alaska and northwestern Canada) and thirty worldwide (with 28 Pika species living in Eastern Europe and Asia). An ancient family, Pika have lived in North America for more than three million years and for even longer in Eastern Europe and Asia, where Pika may have originated as far back as 16 million years ago.

Herbivores, Pika collect a wide variety of vegetation that they temporarily gather (for drying) in mounds called “haystacks” before storing the food in rock crevices or shallow burrows. As winter approaches, the pace at which they forage increases. Pika don’t hibernate; and since they remain active all year, they need to amass enough plant matter to last them through the long winter season.

Though small in size, Pika are enormously charismatic and delightful to watch. You can see them strike pleased poses on rocky perches; scamper across boulders and talus, their mouths filled with grass, clover, forbs, and pine needles; and squeak out high-pitched alarm calls if hawks, weasels, or coyote near their territory.

Unfortunately, predators are not the only danger that American Pika now face in their alpine homes. Climate change—primarily increasing heat and growing aridity—threatens their existence and has already caused localized extinction of several populations in Western states, particularly in the Great Basin.

The higher temperatures experienced throughout the West during the current Anthropocene era create a variety of problems for the American Pika. Evolutionary changes developed over the past 10,000+ years—a high metabolism rate, thick fur, and a high resting body temperature—have allowed the diminutive creature to thrive in cold environments and at high altitudes.

Sad to say these evolutionary adaptations also put the small mammals at risk as Pika “can die when exposed to temperatures as mild as 78° F.” To protect themselves from the heat, Pika have again adapted, moving to higher elevations with cooler temperatures, remaining under the cooling protection of talus slopes and rock piles during the hottest periods of the day, and (for some Pika populations) seeking shelter from the heat “where deep, cool caves are available, such as the ice tubes in California’s Lava Beds National Monument” and in the deserted mines of the Bodie ghost town in the Sierra Nevada mountains.

These latest behavioral adaptations on the part of Pika do not however offer the species long-lasting solutions and even introduce other issues. For one, staying underground for longer periods of time may limit the Pika’s ability to gather sufficient plant material during warmer periods. Because of their high metabolism, a reduced food supply could weaken the Pika, putting additional stress on the little creatures. It could also limit their ability to amass the stockpiles of plant material needed to survive the winter.

Moving to higher altitudes has offered Pika a temporary respite from the increasing heat, but eventually they won’t be able to retreat any further. They’ll simply run out of mountainous terrain. At even higher altitudes they may also lack the diversity of food sources that sustained them at lower altitudes. Moving to higher and higher elevations has also caused populations of Pika to become isolated from one another. Isolated communities become less genetically diverse, more susceptible to disease, and less resilient to changing environmental conditions—even creatures as crafty and long-lived as Pika.

Nor are Pika the only organisms that are moving upslope because of climate change. Trees and other vegetation are moving to higher elevations to find the conditions they need to survive, conditions that used to prevail further down the mountain. Disease-carrying insects also have moved to higher elevations, environments they once could not survive in. And higher temperatures have also brought additional predators to the terrain Pika now populate. While the newly arrived vegetation may crowd out the plant material Pika depend on, limiting their choices and making it harder for them to grow their haystacks, pathogens and additional predators could reduce the range of the Pika, limit their ability to forage freely and widely, and compromise their health.

Increased temperatures at higher elevations have also introduced a new variable for Pika and other creatures adapted to the wintry conditions in alpine environments—a reduced snowpack. Heavy snow offers a deep layer of insulation that protects Pika from the extreme cold during winter months. But global warming has brought reduced snowpack to the Pacific Northwest, the Sierra Nevada Range, and the Rocky Mountains. In recent years, more precipitation has fallen in the form of rain than snow, reducing the snowpack and limiting the insulating ability of the snow that does accumulate. Without it, even creatures as superbly adapted to alpine conditions as the American Pika may not be able to survive the winter.

As serious as the issues that high temperatures are bringing to Pika, drought and the increasing aridity in their alpine environment could pose even more serious problems for the alpine species, further complicating the survivability of these highly-evolved mammals. A 2011 study of Pika distribution in the Rocky Mountains by researchers at the University of Colorado at Boulder (building on research results from two previous studies) concluded that American Pika

populations in areas with chronically low precipitation and lacking sub-talus water sources have been extirpated, supporting previous observations that these dry habitats are marginal for this species (Hafner 1993, 1994). Though the Rocky Mountains provide habitats that are higher in elevation and more contiguous than those in the Great Basin, as the severity of climate change increases in the American West, population extirpations may become more frequent throughout the species’ range. Projected declines in snowpack throughout the western United States (Mote et al. 2005) suggest that apparently stable pika populations in regions such as the Southern Rockies may soon be facing drier conditions.

Other studies concerning the American Pika offer similar speculation about the survivability of the species over the next 30 to 100 years, suggesting that populations in hot and dry climates are far less likely to survive than those in environments that, while hotter than normal, offer higher rates of precipitation, the presence of water sources in areas that Pika inhabit, or both.

While not utterly bleak, the news is not at all reassuring for those of us who love watching this industrious little creature foraging for plants and standing sentry in such favorite haunts as Glacier National Park, Rocky Mountain National Park, the White Mountains in California, and other high-country sanctuaries. I have made near-annual pilgrimages to Yellowstone National Park over the last 20 years and have spent many hours waiting for and watching Pika at the numerous locations where I’ve routinely found them in the park. But the last time I visited Yellowstone, I didn’t see or hear Pika at any of them. And that, unfortunately, is consistent with the Park Service’s own recent assessment of eight of its parks with historic Pika populations. Though Pika are likely to persist and may even increase their numbers at three of the eight parks (including Grand Teton, Great Sand Dunes, and Lassen Volcanic National Park), other parks will see Pika numbers fall, and at Yellowstone National Park—often called the North American Serengeti for the diversity and abundance of wildlife found within its borders—the park service expects “to see complete extirpation of pikas under most climate change scenarios because of warming and loss of connectivity.”

In our profligate use of fossil fuels, we all share the blame for this sad outcome.

You’ll find more information about climate change and the American Pika in the following sources: